I say, the only thing that really helps, in this area, on the part of the printer, is its willingness to adhere to some existing standard or published specification. I work with a new printer these days and as long as I am able to sway the behavior of the press on a given substrate close to a known condition like GRACoL20xx then, all of a sudden, color becomes "manageable". But it takes commitment from management to do so. Usually, the typical policy is to have the proof reflect whatever color appearances the press creates, given a set of inks and substrate combination. There are pros and cons to this approach, indeed but, in my view, that's no enough. It is a start but it's not enough. One of the most difficult aspect of trying to "manage" the overall picture on press, in my humble opinion, is the colorimetry of the inks. I have often seen Magenta come out way too blue (b* of -9 or -8) or Cyan not being "green" enough (a* around -31 or -32). Yellow is usually fine. Black, it depends. But Magenta and Cyan are the worst culprits, in my opinion. I once convinced an ink supplier to change its recipe for Cyan ink and, boy, I loved that a* = -38 value we were getting on press. All of a sudden, matching proofs was a very different game. But it didn't last long because none wanted to accept the increased ink costs (?!). Ink suppliers are quick to point out that can do "anything" for their clients but when it comes down to actually doing it, they're just as quick to point out the economic consequences. Yet, an ink set that is closer to any given specification will help save time and material on press by helping obtain a closer match to color earlier in the run avoiding lengthy make-readies and customer disappointment. / Roger -----Original Message----- From: colorsync-users-bounces+graxx=videotron.ca@lists.apple.com [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of Jan-Peter Homann Sent: 3 juillet 2015 06:46 To: colorsync-users@lists.apple.com Subject: Re: dealing with printers Hello Mike, You raise some interesting questions. From my personal point of view, a workflow with substrate calculated data is currently fine for a inhouse workflow, with proofing and printing in the same company or with a very close cooperation between prepress provider and printer. It does currently not fit the blind exchange of data and proofs based on international standards (ISO) or international specifications (GRACoL, PSO etc... ) ESpecially in the uncoated area, we have the case, that current standards and specs are not addressing papers with a lot of optical brighteners. Instititutions like e.g. FOGRA / ECI are working intensive on this issue and I guess also Idealliance. See e.g. http://www.eci.org/en/projects/fred15 scrool down and have a look at FOGRA52 data Regards Jan-Peter Am 17.06.2015 um 19:19 schrieb Mike Stewart:
Now that we are moving to Substrate Calculated Data sets based on paper white; how on earth do we communicate this to printers. Before OBA's we had GRACoL, Fogra47 - just to name a few. We would colour manage our proofs to GRACoL or Fogra47 (or some print specification), place an Idealliance colour bar on each proof and the customer/printer could measure the colour bar to see if we were in compliance or not to the particular specification.
Now we start from GRACoL Uncoated 2013, change the Paper White values, create a new Data Set and proof to the new data set. Our colour bar on each proof now becomes useless as it will never match to the original GRACoL Uncoated 2013. How do we communicate this to a printer in Asia. How can they now trust our proofs. Do we give them a small single row Press Type Colour Bar that prints within the job itself and also give the printer the specs. for that colour bar. If so, what are the specs. of that colour bar (C,M,Y,K,R,G,B, grey balance swatches, etc). Data for that file would have to be colorimetric and not solid ink and dot gain values I'm guessing.
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